Identifier-translator



OGL l, 1957 D. s. BARLow ETAL 2,808,459

IDENTIF'IER-'TRANSLATOR 8 Sheets-Sheet 1 Filed Dec. 5, 1955 as ARLow "WE/WW s. CRO/:U77: JR.

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Oct. 1, 1957 D. s. BARLow ETAL IDENTIFIER-TRANSLATOR Filed Dec. 5, 1955 `8 Sheets-Sheet 4 Il l o. s. 'aA/PLOW NVENTO G. amori/MJA A TTOR/VEV 8 Sheets-Sheet 5 S maxx /Nlv/ENTORS l0. s. BAR/ ow w mw D. s. BARLow Erm.

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Oct. 1, 1957 Filed Dec. 5, 1955 'lll 'Il JMMQ sa@ SS G. B. CROFUTJR. BY 4 A TTORNEY Oct. l, 1957 D. s. BARLow Erm.

IDENTIFIER-TRANSLATOR 8 Sheets-Sheet 6 Filed De. 5, 1955 D. s. BARLOW y /N VE NTO/QS G. B. CROF U TT, JR.

A TTORNEV Oct. 1, 1957 D. s. BARLW ETAL IDENTIFIER-TRANSLATOR 8 Sheets-Sheet 7 Filed Dec. 5, 1955 OFI/T7', JR.

ATTORNEY D. 3. BARLOW N .Sl

D. S. vBARLOW EF AL IDENTIFIER-TRANSLATOR Oct. l, 1957 Filed Deo. 5, 1955 my new; M Si F F WT. m ww. W w A B.. 5.8 D.G. S R mw N h w 2,808,459 IDENTIFIER-TRANSLATOR Dick S. Barlow, Redondo Beach, Calif., and` George VB. Crofutt, Jr., Verona, N. J., assignors to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York ApplcationDecember 5, 1955, Serial No. 550,937'

13 Claims. (Cl. 179-18)` This invention relates to identifying andA translating devices, and particularly to apparatus for deriving equipment location designations of telephone stations and other specific data which may be useful in telephony or for other purposes. More particularly, the invention is in the nature of an improvement over theV arrangements described in Patent No. 2,749,387 to D. S. Barlow and G. B. Crofutt, Ir., issued on l une 5, 195,6. l

The above-referred to patent discloses a telephone line identifier capable of automatically identifying the directory number cf a calling station. Although completely operative in its intended usage as a directory number identier, this apparatus is not arranged for determining the associated equipment location designation of the telephone line, or number and type of ringing currentY if the directory number is already available.

An object of this invention, therefore, is to provide` for the derivation of the associated equipment number when the directory number alone is available, as is the case on incoming calls.

An additional object of this invention is to provide simultaneous identification of both the equipment and the directory number of a telephone station for originating calls.

A further object of thisinvention is to provide for; the detection of an idle line to a private branch exchange.

The invention accomplishes these and other objects by providing two separate but interconnected arrangements for identifying equipment and directory number designations. Means are provided for obtaining ingress to a directory number network matrix at a particular crosspoint designating the directory number to be translated. All other crosspoints are simultaneously grounded to, pre,- vent interference with the translation. A high frequency signal source is then applied to the designated crosspoint, which signal may be subsequently detected in a separate equipment number network matrix for determining the associated equipment number.

A feature of this invention includes apparatus for detecting and selecting an idle private branch exchange'or P. B. X line. This apparatus includes means for successively neutralizing, or grounding, all of the idle P; B. X line equipment terminals in the equipment number matrix except the one to be selected.

The universal application of this invention may be noted from the features of complete identification and translation services that it provides for a telephone central otlice both on originating and incoming calls. On originating calls, the apparatus is adapted to provide identication of the directory number, class of service and the equipment number of the calling party simultaneously.

With respect to incoming calls, wherethe called line directory number is registered in a sender, the equipment number of the called partyI las lwell as the type of ringing current required, both of `which are essential tothe establishment of a connection to the called party, are obtained through the translation of the corresponding directory number.

nited Stats arent@ 2,808,459 Patented Oct. 1, 1957 ICC ` 'Fig'. "l shc'swsk a telephone line including four parties or stations connected thereto, a station identication circuit for determining which of the four parties is employing the facilities, a switching train for extending the line to a trunk, a private branch exchange group, equipment and directory number terminals and connections therebetween;

Fig. 2A, shows in detail a primary network of passive electrical elements associatedy with the directory number ter-,rrlinals of Fig.1 l, means for grounding a center terminalin certain of said passive elements, means for applyiii'g` a direct-'current voltage in certain others, and means for applying a high. frequency signal to` a selected passive element;

Fig.v 3 shows a secondary network associated with the horizontal elements of the primary network of Fig. 2; Y

Fig., 4 showsa secondary network associated with the vertical lements of the primary network of Fig. 2, and also the three` additional primary networks andk their six associated secondary networks and further, a class network;

Fig, 5 shows in detail a primary network associated with. the equipment number terminals of Fig. l;

` Fig. 6b indicates a secondary network connected with the horizontal elements of the primary network of Fig. 5,; Fig. 7 indicates Val secondary network connected with the v e'rtiCal elements of thenetwork of Fig. 5; Y

VPig.- 8.' i's a lcondensed circuit diagram arranged to aid iny disclosing certain electrical characteristics of a primary network;

Fig. 9 is a condensed arrangement of a portion of a primary network to better disclose certain. other characteristics of said network; and n Fig. 10 shows the manner in which Figs. l to 7,l inclusive should be arranged.

Fig. 1 shows a telephone line L connected to the terminals of a switch LS7 in a central otce. Four tele.- phone stations, orv parties, are connected to the line L, each of the stations A, B, C 4and D having a unique directory number individual thereto. For exemplary purposes it has been assumed that station A has the directory number 3847 individual thereto andan equipment loca,- tion designation, or number, 4000, shared in common withv stations B, C. and D.

When a call is originated on the line L by stationr A, for example, the line is extended in the conventional manner byline switches LS1, LSZ, and LSX, which may be any appropriate construction, to the trunk TR from which the connection is then further extended by a register sender (not shown) in accordance with the dialedy called oiice code registeredtherein. Since the manner in which the line L is so extended is not essential to the understanding of the present invention, the apparatus for effecting, theextension will not be described.

Fig.V l also shows a station identification circuit.Sl-r which, whenrelay CI is operated, is connected to the tip andrrillg conductors T and R of the trunk. The circuit SIC vmay be of thertype disclosed in Patent No. 2,306,173 issued'to M. A. Logan on December 22, 1942, its purpose being to determine which of the stations, A, B, C tor D has'loriginateda call. When the determination has been made,` the party identilcation of the calling station is registered by the operation of one of the four relaysA, B, 'C' or D. The latter constitutes a party: register which is either temporarily associated with the trunk for. the time taken to identify the directory number of a calling stationl as set: forth in the above-referredk to patent of Barlow and B. Crofutt, Ir., or is permanently associated therewith. Thus for example, if the call is originated by station A, the station identilication circuit SIC will determine the fact and cause the operation of relay A of the party register, which relay when operated, locks to oit-normal ground over its locking winding to perform additional functions later described. In the same manner, if the call is originated by stations B, C or D the appropriate station identication will be made and cause the operations of relays B, C or D, respectively, in the party register.

The sleeve terminal S of the line is connected by a conductor to a terminal 4000 (for the line L) in an equipment number terminal group indicated in Fig. 1 by the vertical column of terminals under the legend Equipment Number Terminal. This terminal 4000 indicates the equipment location of the line L on the line switch LS1. If the telephone exchange in which the invention is to be practiced has a capacity of 10,000 lines, there would be up to 10,000 terminals in the equipment number terminal group, each terminal in the group designating a particular location on the terminal banks or contacts of the line switches on which a line is terminated.`

In some automatic telephone exchanges, particularly those in which the lines terminate on non-numerical switches of the crossbar types, for example, there is no correlation between the equipment number termination of a line and the directory number assigned to' the sta- 'tion on the line, or, if there be more than one station on group of cross-connecting terminals which, in Fig. l, is

illustrated by the vertical column of terminals under the legend Directory Number Terminal. Each of the lines in the central oiiice is connected to its associated'equip- 'ment number terminal whichin turn, is cross-connected to the diretcory number terminal.

Thus, for example, terminals of line L which have been assumed to have an equivalent location number of '4000 is extended by a conductor to equipment number vterminal 4000. Line L however, is provided with four stations A, B, C and D of which it has been assumed that -station A has the directory number 3847. Accordingly, a conductor is extended from equipment location termi- Vnal 4000 to directory number terminal 3847. In the same manner, three other conductors, one for each of the other three stations B, C and D, extend from equipment number terminal 4000 to three other directory number terminals in accordance with the directory num- 'bers severally assigned to stations B, C, and D. From 4the equipment terminal 4000 of line L an additional conductor 346 is extended through a termination network R1 and C1, explained herein, to terminal 4000 of the primary network PEN of Fig. 5. The structure and func# tion of this primary network and that of Fig. 2 and the associated secondary networks also will be described herein.

The wiring arrangement of the equipment number and directory number terminals for the lines of a P. B. X (private branch exchange) permit the identification of the one directory number to which a call is to be charged independent of the particular line in the group that initiates the call. For this purpose, all the directory number terminals of the P. B. X line group in Fig. 1 are extended to a collector network comprising a resistor R3 for each terminal, connected in parallel to a grounded common resistor R64, from which a conductor S is further extended into primary network PDNfA shown in Fig. 2. As described herein, conductor 5 is connected to a passive element 1100 in primary network PDN-A, thereby indicating that the directory number to which calls made from a line the P. B. X group are to be charged is 4 directory number 1100, which is the number identified whenever a line in said P. B. X group originates a call.

Additional connections from the equipment number terminals of each of the P. B. X line group stations 1000, 1001 and 1047 are made to corresponding circuit designations in the primary equipment number network PEN of Fig. 5, over conductors 345, 344 and 343.

It may be seen from the above that the wiring arrangement of Fig. l provides one identifying terminal individual to each of the directory numbers of the subscriber stations in the ofrice, and one identifying conductor for all of the lines of the P. B. X group. Also, as was pointed out in the above-mentioned Barlow-Crofutt patent, if a source of alternating potential is applied to the sleeve conductor SL, a circuit would be completed through each of the directory termination networks of Fig.1. The potential available in each of the tour conductors 1, 2, 3 and 4, or if the call originated on a line of the P. B. X group, the potential available on the conductor 5, common to the group, may be utilized for purposes of directory number identification. As referred to herein, the signal power source is an oscillator OSC indicated sc-hematically in Figs. 1 and 8 which, at the appropriate time, is .applied to the sleeve conductor SL of the connection through the contacts of relay SIG (Fig. l) which is operated by any suitable means at the required time.

Fig. 2 shows an arrangement of one of the primary networks PDN-A, the other three PDN-B, PDN-C and PDN-D being indicated in the lower portion of Fig. 4. The number of primary networks provided in an exchang depends upon the largest number of subscriber stations which are connected to any one line. lt is assumed in this embodiment that the four stations A, B, C and D on the line L represent the maximum number of stations on a line. Acordingly, one primary directory number network PDN-A and two associated secondary networks SDV (Fig. 4) and SDH (Fig. 3) are provided for all stations in the exchange corresponding to station A, similar arrangements being provided for stations B, C and D, respectively. Connected to each of the common terminals of each of the passive elements in the primary networks PDN- is a gas diode GT vadapted when ionized to ground said common terminal. Means to be described herein are used to selectively energize all of the gas tubes in the primary networks PDN except one, preparatory to translating a particular directory number to its associated equipment number.

A separate primary network PEN similar in some respects to that of Fig. 2 is shown in Fig. 5. In this primary network, however, a gas diode is connected to the mid-points of each of the'ooupling networks, or passive elements, which are associated with the lines of the P. B. X group only. Through selective energization of these gas diodes, an idle private branch exchange line may be determined by means to be explained herein.

This network (Fig. 5) represents all of the equipment numbers in a central office regardless of the number of stations associated with a particular telephone line. In the embodiment illustrated, primary network PEN alone services -all of the primary directory number networks PDN-A, PDN-B, PDN-C and PDN-D. Individually associated with primary network PEN are two secondary equipment number networks, ESDH and ESDV iilustrated in Figs. 6 and 7, respectively.

The primary network illustrated in Fig. Z and also the one shown in Fig. 5 comprises a network of up to 10,000 linear, bilateral, passive electrical elements. By a linear, bilateral, passive, electrical element is meant an element in which the amplitude of current therethrough is linearly affected by the voltage applied across said element, but is not affected by the polarity of the applied voltage. Thus, for example, a resistor, an inductor, a capacitor or a network of these elements in combination is meant to be included within the definition of :a linear, bilateral, passive, electrical element. .It Vis .understood thatin this description and .intheclaims the 'expression linear, bilateral, passive, electrical element .respectivelyrconnected Vtotwo conductors in two groups of 100 'conductors each. For purposes of illustration thesey two groups of'conductors are shown in Figs. 2 and 5 asdisposed Vin .coordinate arrangement, it being understoodthat :the conductors in `each group are insulated fromveach other and from `the conductors in the other group. Theconductorsin the horizontal group of 100 conductors'are designated from 00XX 99XX while the conductors in the vertical group are designated XX XX99. It may :be seenthatifapassive element is connected toa conductor in the horizontal group which has a particular thousands and hundreds numerical designation andto .a conductor in the vertical group'which has a .particular tens -and unitsdesignation, the-passive-element joining the two conductors will designate .a fourdigit number composed of the thousands and hundreds digit designation of the horizontal conductor to which the :element is connected and the .tens and units designation of the .vertical conductor to which the element is connected. Thus, for example, passive element 4000 in.Fig..5 ihas .the outer terminal of Vits component .(a) connected .to horizontal conductor 40XX.and the outer terminal of its component (b) .connectedto vertical conductor.XX00.

.In .thesame manner .each passive element is .joined to.a.horizontal .conductor and a vertical .conductorin Va primary network todesignate 4a four-digit. number. Since the primary network has a capacity of 10,000 numbers, a similar number of passive elements, each suitably connected to a horizontal and vertical conductor, will indicate eachof the 10,000 numbers.

VThe .Equipment Termination network comprises a capacitor C1 and resistor Rlconnectedvas-shown to the equipment number terminals. The Directory Termination network comprises in addition ,a resistor "R2 con nectedtto .a class terminal Vin accordance with/the class of service to which the station is entitled.

From the termination networks of each of the stations, `aconductor is extended tothe common .terminal of the two components (a) and (b) of the appropriate passive element in network PEN in accordance with 'the equipment locationnumber of the line, and also to one of the'four primary networks PDN-A, PDN-B,"PDNC and PDN-D in accordance with the directory number of the station thereon. 'Thus conductor 1, associated with station A having the directory number 3847, joins a termination network connected to directory number terminali3847 with the common terminal of passive element '3847 in primary network PDN-A (at the intersection of conductors SSXX and )9(47). In a similar manner conductor 346 extends equipment number -terminal 4000 from a termination network to the common terminal of passive element 4000 in primary network PEN. Thus, each station in the central oice'has a passive element in the involved primary network PDN corresponding to its directory number and a passive element in primary network PEN corresponding to the line on which the station is located.

The conductors connected to lines of private branch eX- change groups aresimilarly treated.

However, in contradistinction to the instance of the multiparty sit-uation.where one equipment number may have two or more directory number designations, in a P. B. `X arrangement several equipment-number designations may have only. on directory number designation. Consequently, whereas withrespect to a multiparty telephone situation only one passive' element in primary net- -worklPEN is utilized to designate-the associated 'equipl.ment number, in-thefcase of'a P. B. X line group .twb lor more passive'elementsin primary network PEN are used to represent the severall equipment numbers associated with a single directory'number. It may bepointed out lthatwhere each line of a private vbranch .exchange l group is .to be charged for its own calls .and therefore `it is necessary to identify its vown directory number .upon

.the origination vof 'each of such calls, connections .are

madeto separate or individual termination networks and thence to-separate passive elements in the primarynetworks PDN.

'Where, however, `calls originating on the lines of a P. B. X group are tobe charged to one line only, it then becomes necessary to. identify only the number of ,the latter-line upon the origination of a call from any line inthegroup. In this event,the directory number terminals of the P. IB. X group are extended to a collector network (Fig 1) comprising a resistor R3 for each station, which is-connected vin common to `a grounded resistor R64 whence an identifyingrconductor -5 is then .extended-to apassive element in the appropriate directory number .PDN-. lIn the arrangement `shown in Fig. 1, the callsfrom the-P. B..X lines are assumed to be charged to directory number lltlgjaccordingly, identifying conductorS is connected to passive element 1100 in primary network PDN-A.

Also-associated with each of the primary networks PDN- and PEN are relay Agroups GRI and GRZ, controlled, ,for example, by a digit scanning circuit similarto that shown in Fig.-9 in the above-referred to lBarlow-Crofuttjpate-nt, for grounding all primary bus bars not actually being scanned at a particular instant. This. arrangement helps to prevent false operation of `the identier dueto possible` feedback of 'the identifyingpotential through the interconnected `bus bars. Relay groups GRS and GR4 areradapted to perform the same function inthe secondary networks.

.Different lines in an exchange are entitled to diiterent classes of` service. It istherefore necessary to determine the class of service to which a subscriberfis entitled when he establishes a call, as well as his directory number. For this .purpose there is provided a class network shown in Fig. 4 which is similar in arrangement to the primary networks. There is also provided a group of class terminals shown in Fig. l to which the termination network of .each station entitled to the same class of service'is connected. A class identifying conductor, for Aexample conductor 6, is thensused to connect the class terminal with the passive element inthe class network which identities said class by some digit or character indicative of the class. Y Y

'Separate class terminals FRA, PRB, FRC and FRD are provided for the four directory number terminals connected to equipment number terminal `4000. These four class terminals represent separate connections to the class network for stations A, B, C and D. Although the fourestations generally would receive the sameclass of service, for example, iiat rate service, individual class connectionsare made to facilitate identification of the type of ringing current necessary to reach the party on incoming calls to the central office. Other class terminals (not shown) may be'used for diierent service classes, for example, message rate, `coin class, etc. In each instance where more than one party is connected to the same line, separate class terminals are aitorded for each party to facilitate identification of the party and the type of ringing required.

Previously it has been pointed out that if a source of alternating-current potential is applied to the sleeve conductor 'SL of an extended connection, that potential becomes available on all identifying conductors, for instance, yconductors 1, 2, 3 and 4 severally connected to the termination networks of the stations on'the line L. The potential also is availablein the case ofline L, on conductor 346 which is connected to a corresponding passive 'element' in primary network PEN; It maybe seen from the above that said potential will be extended in each network connected to said identifying conductors, to the pair of vertical and horizontal conductors therein to which the associated passive element is connected. Since the party identication of the calling station on the line is determined by the operation of one of four relays A, B, C or D of the party register, as previously noted, the potential thus made available at each pair of conductors in each of primary networks PDN could be used, if desired, to activate suitable responsive apparatus under the control of the operated party register relay to provide an indication of the directory number of the callin station.

At the same time the conductor extending from the equipment number terminal to a passive element in primary network PEN Will activate a pair of horizontal and vertical conductors connected to said passive element, which again if desired, may activate associated responsive apparatus to provide `an indication of the equipment number of the calling station.

Information in a one-outoften thousand code, however, requires complex apparatusA to transmit and record, making it desirable to compress the code. In this case, Vthe individual directory numbers and equipment numbers are translated to a two-out-of-iiveV code. Since the twoout-of-ve code. requires but tive code conductors for each digital order of the directory number, twenty code conductors (tive for each digital order) are required to transmit a four-digit directory number and another twenty code conductors are required to transmit a. four-digit equipment number identification for each one of 10,000 stations.

In the two-out-of-ve code, any digital value from O to 9 is expressed by the energization of two, and ,only two, out of a group of tive conductors or other elements. Each of the elements is given a numerical designation such that, for each digital value except 0, the Sum of the designation of the two conductors, or elements, yactivated to express a digital Value, indicates that value. The code is as follows:

Code Conductors or or Other Elements and Their Designation Digital Value An inherent advantage of the two-out-of-ve code shown in the embodiment is that each digital value is expressed by two elements of the code, and only two, such 4that if more or less than two `elements are activated, an error is recognized.

In order to compress the directory and equipment numbers into the two-out-of-ve code, secondary networks SDV and SDH are provided for each primary network PDN-, and secondary networks ESDV and ESDH are provided for primary equipment number network PEN. In each instance the secondary networks SDH and ESDH are used to express the thousands and hundreds digit of the identified number in the two-out-of-ve code and the secondary networks SDV and ESDV are used to express the tens and units digit of the number in the twoout-of-ive code. Figs. 3 and 6 show in detail the secondary networks SDH and ESDH associated with the primarynetworks PDN-A and PEN, respectively. It is understood that a similar pair of secondary networks SDH and SDV is provided for each of the `other three 8 primary networks PDN-B, PDN-C and PDN-D as indi4 cated in the lower portion of Fig. 3. Each of the secondary networks comprises two groups of ten pairs of conductors, one group of ten pairs being shown in Fig. 3 in vertical alignment to indicate the ten values 0XXX QXXX of the thousands digit, the other group of ten pairs being shown in horizontal alignment to indicate the ten values XXX X9XX of the hundreds digit.

The two vertical conductors OXXX, for example, are extended to the Vtwo code conductors 4 and 7 of the ve code conductors 0, 1, 2, 4 and 7 included within the bracket TH, to indicate the 0 value of the thousands digit, while each of the other pairs of vertical conductors lXXX 9XXX are similarly extended to the particular two-out-of-ve code conductors within the bracket TH in accordance with the code representation of each of the other nine values of the thousands digit.

In the same manner the two horizontal conductors XQXX, ,for example, are connected to two code conductors 4 and 7 within the bracket H to indicate the 0 value of the hundreds digit, while the other pairs of horizfontal conductors are similarly extended in accordance with the code representation of the digital value.

To each pair of vertical conductors is connected ten pairs of passive linear elements, each pair of said elements having a common terminal, each pair being individual to each directory number having the same thousands digit but a different one of the ten values of the hundreds digit. Connected to each pair of horizontal conductors are ten pairs of similar passive elements, each pair of said elements being joined at the common terminal with the pair connected to the vertically crossing (but insulated) conductors, one pair being individual to each directory number having the same hundreds digit but a different one of the ten values of the thousands digit.

For example, in Fig. 6 passive element 40XX, comprising four components with a common terminal, has its two horizontal components connected to the vertical conductors 4XXX and its two vertical components connected to the horizontal conductors XDXX. Element 40XX, therefore, is individual to all equipment numbers having the thousands digit 4 and the hundreds digit 0. It is evident from Fig. 6 that the ten passive elements each having their two horizontal components connected to the pair of vertical conductors 4XXX will each be individual to equipment numbers having the thousands digit 4 and that the ten passive elements each having their two vertical components connected to the pair of horizontal conductors XilXX will each be individual to equipment numbers having the hundreds digit 0. The same arrangement is followed with respect to each of the other passive elements and each of the other pairs of conductors shown or indicated in the secondary network ESDV of Fig. 7, SDV of Fig. 4 and SDH of Fig. 3.

Thus the secondary networks SDH and ESDH form squares, each square bounded by the crossing of two of the ten pairs of vertical and horizontal conductors, the venclosure of. each square containing a four-component passive element whose two horizontally disposed elements are connected to the pair of vertical conductors to designate the thousands digit of a directory or equipment number, while its two vertically disposed components are connected to the pair of horizontal conductors to designate the hundreds digit of the number. However, since there are ten horizontally disposed passive elements between the same pair of vertical conductors, it follows that each of said pairs designates a number which has the same numerical value for its thousands digit, and since there are ten vertically disposed elements connected to the same pair of horizontal conductors, it further follows that each of said pairs designates a number having the same value for its hundreds digit.

It may be seen that since each pair of vertical conductors tlXXX 9XXX is connected to a pair of the code conductors t), 1, 2, d and 7 within the bracket TI- I 9 in accordance with :the1code representation 'of-.each `of the ten values of Ythe thousands digit,.theelectrical activation of any pairof `vertical.conductors by 'the application of a potential thereto from ytheconnnon .terminalof the passive element within the square willresult in the electrical activation of the two code conductors ttofwhich said -pair of .vertical conductors is connected, thereby -to indicate .the .thousands digit represented by said pair of vertical Yconductors -in the two-out-of`llve code.

`The .horizontal conductors yare similarly arranged. The activation of a pair of code conductors (l, 1, 2, 4 and 7 within the bracket H indicates thegparticular value in the two-out-of-ve .code `of the hundreds digit'of the passive element to which .thepotential -is applied. Thus if apotential is applied to `the common .terminal of the-element within a square formed by :two vertical and two horizontal conductors, one pair of .code conductors 0, -1, 2, 4 and -7 withinbracket TH will beiactiva'ted 1to1 indicate the code of the thousands digit value represented bythe enclosing pairof vertical conductors -andlone pair of -code conductors 0, 1, 2, 4-and 7 within the bracket H will 'be similarly .activated to indicate the code'of vthe `hundreds digit value representing the enclosing pair of horizontal conductors. Fig. 6 .for example, a potential applied to the common terminal .thereof will cause the activation of the .code conductors and4 within the bracket "IHand code conductors .4 and 7 within the bracket H indicating `the thousands .digit 4 in -the two-out-'Of-ve zcode andthe .hundreds digit `0 in the same code, respectively.

The arrangements 'of passive elements Vin l.the-secondary networks .SDV -and ESDV, Fig. 4 'and Fig. 7, respectively, which are .reserved Yfor the `indication of all tens and units digits .ofdirectory and equipment 'numbers respectively, are arranged ina manner similar kto thato'f primary networks ESDH and SDH. ln each `of the 100 squares formed by the ten pairs of vertical conductors XXOX XX9X and the ten pairs of horizontal conductors XXXO m9 is -connected a four-component .passive element, for example, elementXXt) :of Fig. 7. In this case, the .two horizontally disposed components rare connected to the pair of vertical conductors XXOX to indicate `an equipment number having the tens digit 0, and the .two vertically/disposed components :are-connected to the pair of horizontal Vconductors XXXOto indicate an equipment number .having the units digit 0.V Since the ten .pairs of vertical -lconductors XXUX .XX9X are connected to the -code conductors -0, v1, 2, 4 and `7 within the 'bracket T, and .the ten pairs of lhorizontal conductors XXXO )0(X9 are connected to the code conductors .0, 1,Y.2;, 4 yand 7 within ztherbracketlU, the application of a potential .to the common point of the element .XXtl will activate -code conductors 44 and17 'within bracket T to .indicate the tens digit 0 in =the 'two-'out of-ve code, vand the code conductors v4 and 7 within-the bracket -U 'to indicate 'the units digit 0.in .the-Lsame-code.

The connection between a ,primary network PDN- or PEN .and the Vassociated secondary networks SDH and SDV or ESDH and ESDV, respectively, is established by (1) extending the horizontal conductors 00XX 99XX of a primary net-work severally to the common terminals -ot the passive elements of "the associated jsecondary network vSDH or ESDH in accordance with the thousands andahundreds numerical designation fof the iconductors and thoseof .said passiveselementalandi?) fe'X'e tending the vertical conductors XXlQ XX99 of fthe primary networks 'BDN- and PEN severally to the c'ommon terminals of the passive elements of the associated secondary .networks SDV and ESDV in accordance-'with the identity of the tens and units vnumerical designation of the conductors and those Vof said lpassive elements.

Considering, for example, Vpr-imary networks lPEN .and its vtwo associated networks vESDH and ESDV, horizontal conductor 40XX in said .primary networkis connected to `the common terminal of passive lelement 40XX .in the In the case 4of -the'passive element 40XX`0f Asecondary network fSDH,` vother zho'rizontlrconductors -XX from said-primary 'networks PEN being :similarly extended 'tov otheri passive 'elements in `said :secondarytneb work-ESDH. Similarly, vertical conductor vXXtIU from .primary Inetwork 5B1-EN 'fis vconnected to the common -terminal of fpassive element `XX00 in 'secondary network ESDV,other verticalconductors XXv-vfrom saidprimary network being similarly "extendedto passive elements in secondary network ESDV.

The described 'relationship `between vthe primary .network PEN and itsassocia'ted networks EISDV=andfESDH i-s `-illust`rative `-of --an identical relationship rbetween the remaining primary networks -PDN'- and 'theirass'ociated secondary networks. :It `may be seen that a signalpoten- -tial 'furnished 'over a'horizontal conductor-' -XXof the primary network to the common'termi'nal of a'similaily designated passive element in 'thesecondary network ESDH -or-SDH 'will furr'iish code -indications of a directory-'number for equipment-'number-having 'the thousands digit value indicatedv by the thousands digit `designation ofthe pai'rfof Vvertical conductors in the secondary net works '.ESDHor SDHto which .the two 'horizontalrco`rnponents `of .said-element are connected, and a hundreds digit =v`alue indicated by the .hundreds 'digit designation of the pair of'fh'rizontal. conductors in ysaid ysecondary networks toewhich :the two verticalcomponents of:said element are connected. Similarly, a signal potential applied -`over a vertical-conductor XX- to the common terminal fof 4the similarly designated element XX- lin the secondary network ESDV or SDV will furnish tens and units digit code indication of a directory or equipment number having the tens digit value indicated by the tens digit designation of the pair of vertical conductors to which-the two horizontally disposed components ot' Said element areconnected, and the units digit value indicated by the units digit designation of the pair of horizontal conductors to which the two vertically disposed components of said element are connected.

The two-`outeoftive conductors 0, 1, '2, 4 and 7 of the thousands, hundreds, `tens and units digits shown in Figs. 3, 4, 6 and 7 lare connected to suitable responsive `apparatus (not shown) for indicating the directory or equipment :number represented fby :the `code. .As indicative io'f'" the .apparatus which may be advantageously used in conjunction with vthe present invention reference .may be made to the above-mentioned patent `to D. S. Barlow and G. B. Crofutt, Ir. which 'is lherewith incorporated by reference.

When `a call is initiated from station A, line L is fextended in the usual manner over switchesY LS1 LSX to the trunk TR, the vmagnets of theswitching train being held operated by ground over the normal contacts'of re-v lay SIG. -After the oice co'd'e of the '-called station is dialed and registered in the registers of the sender (not shownf),:.said sender determines from this code that the call requires the 4recording o'f the'directory and/ or equipment number of the calling station. Relay CI is then operated 'in any suitable manner, whereupon the tip and ring conductors T and R ofthe trunk are switched to 'the station identification circuit `SIC,--w`hich then operates to determine the id'entity of 4'the calling station in the manner described in the above-mentioned patent to M. A. Logan. Since the call Twas placed at station Afcirouit SIC, as a consequence fof the test'it makes over the line L, 'ca-uses fthe operation 'ofrelay A fof the party register,

which relay loc'ks over its locking winding under the control of an ott-normal ground ON, -and applies ground to conductor 7 which inritunn exten'c'is-to an inp'iit fgate circuit IPG shown in box form .in Fig. 1. The function of circuit IPG, explained in detail in the above-referred to Barlow-Crofutt patent, is to energize the responsive apparatus for the particular network PDN- on which the calling station is represented. Further operations which will not be described 'in detail herein as they -a're 'notessential fto an lunderstandingfof the present invention;y

may be performed in accordance with the teachings of the above-mentioned Barlow-Crofutt patent, for example, to complete a circuit from the oscillator OSCUto the sleeve conductor SL through contacts of relay SIG over conductor 46, after a check of sleeve impedance by circuit SCK over conductor 15. Reference to Figs. 10 of the above-referred to Barlow-Crofutt patent may be made for an examination of suitable apparatus.

The oscillator may be of any suitable construction. It should have a low impedance and be adapted to generate a high-frequency current. This frequency should be higher in frequency than that of the noise which, being generally within the limits of l to l0 kilocycles, suggests that the oscillator frequency might be 30 kilocycles by way of example. The characteristics of the oscillator OSC, the constants of the termination network connected to each of the directory number terminals and the constants of the passive elements in the primary networks PDN- and PEN bear a relationship to each other which is best explained by consideration of the circuit diagrams shown in Figs. 8 and 9, the former schematically indicating the electrical conditions on the sleeve conductor SL of a line L for example,'while the latter indicates the relationship between the oscillator OSC and the passive elements of a primary network PDN-.

Ina switching train of an extended connection as, for example, in an exchange which employs crossbar switches, the switch train comprises a number of switches each of which, after being operated to extend the line, is held in an operated position by a magnet connected to battery and by a ground applied to the sleeve conductor SL. The lines that are normal on the other hand, have the magnet of the rst switch normally connected to their respective sleeve conductors. This is shown in Fig. 8. All of the sleeve conductors in the exchange are, of course, extended over conduct-ors to the equipment nurnber terminals, and tothe appropriate passive networks in primary network PEN, as previously explained.

When the identifying signal is to be applied by the oscillator OSC to the sleeve conductor SL lof the extended connection, the ground holding the magnets of the switch train at the normal contacts of relay SIG is replaced on the operation of said relay by ground through the inductance IND. The resistance of this inductance should be low to provide suilcient current to hold the magnets of the connection train in an operated condition..

The presence of battery through the magnets on the sleeve conductor SL of the lines in a non-calling condition, and the fact that all the sleeve conductors in the exchange are interconnected through the horizontal and vertical conductors of the primary networks PDN- and PEN requires that the termination network connected to each of the directory and equipment number terminals be provided with a capacitor C1 to prevent the establishment of battery current drain circuits through each of the magnets, conductor SL and termination resistors R1.

Previously it was noted that the oscillator OSC should have a low impedance. The reason for this is that the impedance of said oscillator must substantially match the impedance of the termination element R1 which must itself be low to prevent any appreciable signal potential from being applied yto horizontal and vertical conductors of a primary network other than the two conductors therein the which element XXXX marking the directory or equipment number of the station to be identified is connected. Under these circumstances and considering that the impedance of each of the passive elements must be high in comparison with the termination impedance Rl, the quantity of signal potential available at the two horizontal and vertical conductors of the primary network to which the passive element of the station is connected is high, while that which is available on other conductors of the network is low, thereby providing at each of said latter conductors a 12 Y quantity of signalpotential which is ineffective to actuate the responsive apparatus.

Fig. 9 indicates yan abbreviated portion ofthe primary network PDN- to illustrate the distribution of signal p0- tential. In this ligure the oscillator OSC is shown on the locationof the termination impedance R1 while the Vcomponents aand b of the station element 3847 are shown connected respectively to the vertical conductor XX47 and the horizontal conductor 38XX. Along 'the vertical conductor XX47 are connected the components a of other elements XX47, said elements connecting with their respective termination impedances R1 to ground but for which, with respect to element 3847, the oscillator OSC has an equivalent impedance shown in place thereof. Component b of element 3847 as well as components b of all elements representing stations, the thousands and hundreds digits of whose directory nurnbers begin with 38 are connected to horizontal conductor 38XX.

For exemplary purposes, it may be assumed Ithat the termination impedance R1 is 100 ohms (the impedance of the oscillator OSC being also in the order of ohms), the impedance of each component a and b of element XXXX is 10,000 ohms and that the signal potential is appliedat the common terminal of an element XXXX, for instance element 3847. The quantity of potential available on vertical conductor XX47 is largely controlled by the number of elements A connected to vertical conductor XX47. Besides component a of 3847 there are 99 other elements a connecting conductor XX47 to 99 corresponding terminating resistors R1 each of which connects to ground. Signal potential applied to terminal 3847 passes through one l0,000-ohm element a to vertical conductor XX47 and thence in parallel through 99 10,000-ohm combinations of element a and resistor R1 to ground. The signal potential on vertical conductor XX47 is therefore slightly over one-hundredth of the signal applied at terminal 3847. This is the signal which is delivered to a secondary network and thereafter to other circuits to identify the tens and units digits.

In the same way, about one-hundredth of the applied signal potential is delivered on horizontal conductor 38XX. The signals von busses XX47 and SSXX are, in this example, the wanted signals, and the factor one ouchundredth may be called the forward transmission of the primary network. The transmission of the signal from conductor XX47 to any one of the 99 terminals XX47 other than terminal 3347 is determined roughly by the ratio of the impedances of termination R1 and element a. In this example, the ratio is 100 ohms to 10,000 ohms and the transmission is about one one-hundredth. This factor may be called the backward transmission of the primary network and the signals on all terminals XX47 other than terminal 3847 are the unwanted signals.

The unwanted signals are in no way distinguishable from the Wanted signals, and will act on the primary -network in the same manner except that an unwanted signal is smaller than a Wanted signal by the product of the forward and backward transmission, which in this example is one ten-thousandth.

The primary networks PDN- andv PEN are thus arranged such that the small termination impedance R1, in comparison with the larger impedance of each of the components a and b of a passive element, will eiectively attenuate backward transmission through the network, rendering signal transmission substantially unilateral. Therefore, although interconnected, the effect on othervertical or horizontal conductors by a signal applied to a particular conductor is minimal and, in this case, insuicient in magnitude to actuate the responsive apparatus. In addition, the embodiment shown presumes au arrangement such as relays GRI and GRZ, for example, for grounding all 1of the primary conductors not actually being used for the identification of the particular digit being examined by the identifier, thus obtaining a further an arrangement is Ifullydisclosed lin the Jabove-mentioned patentef 3D. S. Barlow and 1B. Cro'futh lr.

In the same manner, and Aby l'substantially similar arrangements as Yprovided for the Yprimary networks PDN- and PEN, the passive elements `in -the secondary networks function vllikewise 4to `provide ,good forward transmission and poor backward transmission through the J'network, `with the Aresult `thatthe .code conductors, although interconnected "by the `secondary network remain substantia'lly isolated -electrically.

It may be seen that fa signal potential available `at CI-Rl of Fig. 1 and Itransmitted over con'ductor`346 to passive elementltil) in Fig. 5 -is lfurthertransrriitted over component a and conductor 40XX'to the center-terminal of the four-.element resistor =40XX of secondary network ESDH (Fig.16. In a similar tmanner and over component b ofpa-ssive element 4000, aportion-of said 'signal is transmitted over conductor XXlltl -to the common terminal of the four-element resistor XX00 of secondary network ESDV v(Fig. 7;.)

That part of the signal-potential which is available at the outer terminals of the two horizontal elements of resistor 40XX is made available on the code conductors 0 and 4 within the bracketTH of the secondary networks ESDH, which potentialis availablefor detection by suitable responsive apparatus, :for example, apparatus shown in-the above-mentionedpatent of D. -S. Barlow and-G. B. Crofutt, fir. In `the same manner., `the signal potential available at the outer terminals of the vertical elements of resistor 40XX are joined 'through conductors XOXX to code conductors 4 and 7 'within the Abracket 'H of secondary network ESDH.

Further, the signal Apotential applied to the common terminal of the four-'element resistor XXGD in secondary network ESDV resultsin the application of apart .of said potential to -code conductors 4 and 7 within the bracket T and to code conductors 4 and 7 within the bracket U.

Having thus. generally described the apparatus comprising the invention, the 4description of its operation now follows:

Assume in the first vinstance that the invention 'is to 'be utilized `in its capacity las a called directory number .to equipment number translator. `In this case the directory number -of a given subscriber station is known from .the sender into which said number Ahas been dialed. It is necessary to determine the corresponding called line equipment number. Assume that the known directory number is 3847. The translation process is commenced by selectively operating the relays DC from the kcalled number registers of the sender to apply a direct-current voltage to all of the `primary vnetwork busses of primary network PDN-A, except those connected to the coupling network of the directory number sought -to be translated. This direct-current voltage will act to lire Vall 'of Athe gas tubeV diodes GT to ground except the ldiode GTA connected .to the mid-point lof the passiveelement 3847. If, now, an alternating-current tone signal in the range of 30 kilocycles, for example, is applied to reither one or the other of vthe two `primarybusses SSXX or XX47 by actuating the approporiate relay AC, the tone vwill be transmitted through the passive element `3847, conductor 1, condenser C1, directory number terminal 3847, 'equipment number terminal 4000, condenser C1, conductor 346 to passive .element 4000 of primary network PEN. The tone .thus appearing on said element may be traced and detected in the manner hereinabove set forth and the decimal designation of the equipment -number =corresponding to .directory number 3847 established.

It may be seen that the application of the alternatingcurrent tone to a :bus connected to passive element 3847 cannot result .in the transmission Iof any substantial signal through conductors other than conductor No. 1 in view of the voltage regulator action of the tired gas tubes which, from an alternating-current standpoint, is equiva- 14 lent to substantially a direct ground placed. at the center terminals of all other passive Aelements in 'the network PDN-A, thereby shunting any spurious currents which mayso appear.

The simultaneous identification of both equipment and directory number of `a 'calling station 'by application .of a signal Eto'theisleeve'conductor have previously Ybeen explained.

The present embodiment also 4provides 'a method of selecting an Aidle private branch exchange line. To a'ccomplish this a gas tube diode GT lhas been provided for each private branch exchange line and'connected between the mid-point of the passive element in primary network v PEN individual tothe equipment 'number of the line 'and ground, as -shown'in Fig. 5. rilonemay be applied to the 'P. B. X directory number ofthe P. B. X group .atthe passive element 111i@ of Fig. 2 l(assumed to be the directory number) 'in a manner similar to 'that of element .3847. As described above, all other paths being shuuted Vto ground, -the ltone will travel over 'conductor 5, through the -collector network resistors R5, directory number terminals, equipment number v'terminals 106), 1001 and 1047, and thence over `conductors 343, '344 and 345 `to passive elements 1047, 1001 'and 1000, respectively, in primary network PEN.

Tone may now 'be detected on several horizontal and vertical conductors in primary network vPEN and their corresponding conductors in the secondary networks ESDH and ES-DV. All horizontal conductors in primary network PEN are ygrounded by operation of relays GRI. Secondary `network ESDV may now be traced for conductors Lbearingtone which in `this case will include conductors XXOX, XX4X, XXXO, XXXl and XXX7. A pair .o'f horizontal and `vertical conductors of secondary networks ES'DV-are now 'arbitrarily selected, for example, XX4'X and Direct-current voltage 'is then applied to the remaining conductors in secondary network ESDV `throughselec'tive Voperation of relays DC'Z. As a result all 'gas `tubes, GT in -Fig. 5 connected to vertical conductors other than vertical conductor XX47 are ionized and tired' to ground. 'Subsequently .relays GRI are deenergized and relays GRZ are energized. yNetwork ESDH `may now be traced in the conventional manner explained above Vfor horizontal and vertical .conductors bearing tone.. In this 'instance only conductors IXXX and XXX (neither of which are shown) will. bear tone. Assuming for the purposes of explaination that other horizontal and vertical' kconductors in secondary network ESDH are bearing tone, an 4arbitrary choice of conductors lXXX and XQ( will be made. All other conductorsV are subjected to a direct-current signal by selective operation of relays D02. This occasions the tiring of all gas tubes GT in the primary network PEN which are not connected to vhorizontal conductor 10XX. As a result, only one gas tube 'GTat the intersection of horizontal conductor 10XX and vertical conductor XX47 remains unred. The equipment number of this idle private branch exchange` linemay now he read as in the nonprivate 'branch exchange case. y

It is understood that the above-described .arrangements are illustrative of the application of the principles of the invention. Numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention.

What is claimed is:

`1. A translator for use in telephone systems comprising Vin combination a first and second coordinate .array of conductors, the conductors in each arraybeing joined by electrical elements at their crosspoints, each of said elements expressing a numerical designation, a plurality of subscribers lines individually connected to at least one .element in each of said arrays in accordance with the numerical designation of said lines, and means for energizing a selected element in said second array, including means responsive thereto for energizing the corresponding element in said iirst array connected to the same line as said selected element.

2. A translation device for use in telephone systems comprising in combination a rst and second coordinate array of conductors, the conductors in each array being joined by electrical elements at their crosspoints, each of said elements expressing a numerical designation, a plurality of lines individually connected to at least one element in each of said arrays in accordance with the code designations of said lines in the respective array, means for energizing a particular element connected between two conductors in said second array including means for grounding the remainder of the elements therein and including means for applying a signal frequency to one of said conductors connected to said element to be energized, and means in said first array for detecting said signal in said element in said rst array connected to said energized element in said second array.

3. In a telephone system comprising subscribers stations and lines, each station having an individual directory number and an individual equipment number, means for identifying said equipment number when said directory number is known, said means comprising a first and second coordinate array of conductors, the conductors in each array being joined by electrical passive elements at their crosspoints, each of said elements in said second array expressing a directory number, each of said elements in said lirst array expressing an equipment number, said subscribers lines being connected to said elements in said arrays in accordance with their respective directory and equipment numbers, means in said second array for applying a high-frequency signal to one of the conductors connected to the element designating the known directory number of which the corresponding equipment number is desired, means for grounding the mid-points of the remainder of saidpassive elements in said second array, and means in said first array for detecting said high-frequency signal and for identifying the element in said iirst array connected to the element in said second array to which the high-frequency signal has been applied.

4. An identifier for ascertaining the equipment number designation of each of a plurality of telephone stations from the directory number of each of said stations, each directory number and each equipment number comprising four digits, including a first and second coordinate array of conductors, the conductors in said second array including two groups of one hundred paths, one of said groups being disposed horizontally and designating the thousands and hundreds digits of said directory number, the other of said groups being disposed vertically and designating the tens and units digits of said directory number, the conductors in said first array including two groups of one hundred conductive paths, one of said groups being disposed horizontally and designating the thousands and hundreds digits of said equipment number, the other of said groups being disposed vertically and designating the tens and units digits of said equipment number, the conductors in each array being joined by passive electrical elements attheir crosspoints, each of said stations being connected to at least an element in each of said arrays, each of said elements in said second array expressing the four digits of the directory number of the station to which said element corresponds, each of said elements in said irst'array expressing the f our digits of the equipment number of the station to whichV said element corresponds, means in said second array for applying a high-frequency signal to one of said passive elements thereinin accordance with the directory number to be translated, means for grounding the remaining passive elements in -said secondarray and means in said first array for ascertaining the element therein at which said signal is rendered effective, said element expressing the desired equipment number.

' 5. An identilier translator comprising in combination a first and second coordinate array of conductors, the conductors in each array being joined by electrical elements at their crosspoints, each of said elements expressing a numericalV designation, aV plurality of lines individually connected to at least one element in each of said arrays in accordance with a code expressing its numerical designation, means for energizing any one of said lines, means responsive to the operation of said last-mentioned means for energizing the elements to which said line is connected, and means for identifying the energized elements in each of said arrays, thereby to ascertain the code designations of said elements.

6. An identifier for ascertaining the directory number and equipment number designations of each of a plurality of telephone stations in a telephone system, each of said stations having a four-digit directory number and a four-digit equipment number, said identilier comprising a first and second coordinate array of conductors, each of said arrays including two groups of one hundred conductive paths, one of said groups in each array being disposed horizontally to respectively designate the thousands and hundreds digits of the directory numbers and equipment numbers, the other of said groups being disposed vertically to respectively designate the tens and units digits of said numbers, the conductors in each array being joined by electrical passive elements at their crosspoints, each of said elements in said first array expressing an equipment number, each of said elements in said second array expressing a directory number, said stations being connected to at least one element in each of said arrays in accordance with the assigned directory and equipment numbers, means responsive to the initiating of a call on any of said stations and means responsive to a potential applied by the operation of said call indication responsive means to the passive elements to which said calling station is connected for producing a group of signals indicative of the directory and equipment numbers of said calling stations.

7. A translator for the lines and stations of a telephone system, each of said stations having an individual directory number and each of said lines having an equipment location number, a first device responsive to a calling condition in one of Asaid stations for ascertaining the directory number of said calling station and the equipment location number of the line in which said station is located, means settable according to the directory number of one of said stations when called, a second device, and means responsive to the operation of said settable means for jointly operating said rst and said second devices for ascertaining the equipment location number of the line on which said called station is located.

8. An identifier translator for ascertaining the designations of telephone stations in a telephone system, comprising in combination a first and second coordinate array of conductors, each of said arrays including two groups of one hundred conductive paths, one of said groups being disposed in a horizontalV array with each path therein designating a pair of thousands and hundreds digits of the designations of said stations, the other of said groups being disposed in a vertical array with each path therein designating a pair of tens and units digits of the designations of said stations, the conductors in each array being joined by electrical elements at their crosspoints, each of said elements expressing a numerical designation related to the conductors to which it is connected, means connecting each of said stations to at least one of said elements in each of said arrays in accordance with a code, means for applying a high-frequency signal to two selected conductors in said second array, means for grounding all the elements in said second array except the one element joining the two selected :conductors, means in said first array responsive to the application of said high-frequency signal for detecting the conductors in said second array to which the signal is i? applied, thereby to identify the passive element in said first array connected to said element in said second array joining said two selected conductors.

9. An identifier translator for ascertaining the direc: tory and equipment numbers of telephone stations in a telephone system, comprising a first and second coordinate array of conductors, said second array including two groups of one hundred conductive paths, one of said groups being disposed horizontally to designate pairs of thousands and hundreds digits of said station directory numbers, the other of said groups being disposed vertically to designate pairs of tens and units digits of said station directory numbers, said first array including two groups of one hundred conductive paths, one of said groups being disposed horizontally to designate pairs of thousands and hundreds digits of said station equipment numbers, the other of said groups being disposed vertically to designate pairs of tens and units digits of said station equipment numbers, each horizontal and vertical conductor in each array being joined by passive electrical elements at their crosspoints, each of said elements in said second array representing a particular directory number, each of said elements in said first array expressing a particular equipment number, means connecting each of said stations to at least one of said elements in each of said arrays, means for applying a high-frequency signal to two selected conductors joined by a particular element in said second array, means for grounding the remaining elements in said second array, means in said first array responsive to the application of said high-frequency signal for identifying the passive element in said first array connected to said element in said second array joining the two selected conductors, means responsive to one of said stations when calling for applying a high-frequency signal to certain conductors in said second array, thereby to activate the passive element expressing the directory number of said calling station, and means in said first array responsive to the activation of said passive element for activating the passive element expressing the equipment number of the station connected to said element.

10. An identifier translator for determining the directory and equipment numbers of telephone stations in a telephone system, comprising a first and second coordinate airay of conductors, said second array including two groups of one hundred conductive paths, one of said groups being horizontally disposed to designate pairs of thousands and hundreds digits of said station directory numbers, the other of said groups being vertically disposed to designate pairs of tens and units digits of said station directory numbers, said first array including two groups of one hundred conductive paths, one of said groups being horizontally disposed to designate pairs of thousands and hundreds digits of said station equipment numbers, the other of said groups being vertically disposed to designate pairs of tens and units digits of said station equipment numbers, each horizontal and vertical conductor in each array being joined by passive electrical elements at their crosspoints, each of said elements in said second array representing a particular directory number, each of said elements in said first array expressing a particular equipment number, means connecting each of said telephone stations to at least one of said elements in each of said arrays, a gas diode connecting each of said elements in said second array to ground, means for applying a high-frequency signal to two selected conductors in said second array, means for ionizing the gas diodes in said second array other than the one connected to the passive element joining the two selected conductors, and means in said first array responsive to the application of said high-frequency signal for activating the passive element therein which is connected to said element in said second array joining the two selected conductors.

ll. A translation device for use in telephone systems comprising in combination a rst and second coordinate array of conductors, the conductors in each array being joined by electrical elements at their crosspoints, each of said elements expressing a numerical designation, a plurality of telephone lines individually connected to at least one element in each of said arrays in accordance with the code designations of said lines in the respective arrays, means for energizing a particular elementv connected between two conductors in said second array including means for grounding the remainder of said elements in said second array and including means for applying a signal frequency to one of said conductors connected to said energized element, means in said first array for detecting said signal in said elements in said first array connected to said energized element in said second array, and means for selecting one of said energized elements in said first array including means for selectively grounding all of said energized elements other than the selected element.

l2. An identifier for determining the equipment number of an idle private branch exchange line, including a first and second coordinate array of conductors, the conductors of each array being joined by electrical elements at their crosspoints, each of said elements expressing a numerical designation, a plurality of subscribers lines individually connected to at least one element in each of said arrays in accordance with the code designation of said lines in their respective arrays, a gas diode connected to each of said elements in said first array expressing a numerical designation representative of a private branch exchange equipment number, means for energizing a particular element connected between two conductors in said second array including means for grounding the remainder of the elements therein and including means for applying a signal frequency to one of said conductors connected to said element to be energized, means in said first array for detecting said signal in said elements connected to said energized element, means for selecting a particular energized element in said first array expressing an idle private branch exchange line equipment number including means for successively and selectively grounding all of the energized elements in said first array other than the selected element in said first array, and means for identifying said selected element.

13. An identifier translator for use in telephone systems comprising a first and second coordinate array of conductors, the conductors in each array being joined by passive electrical elements at their crosspoints, each of said elements expressing a numerical designation, a plurality of subscribers lines individually connected to at least one element in each of said arrays in accordance with the code designations of said lines in the respective arrays, means for energizing a particular element connected between two conductors in said second array including means for grounding the remainder of said elements in said second array and including means for applying a signal frequency to one of said conductors connected to said energized element, means in said first array for detecting said signal in said elements in said rst array connected to said energized element, and means connected to said subscribers lines for identifying the type of ringing current required to ring said subscribers stations.

No references cited. 

